Pokemon the Series Season 9 Episode 44 Gathering the Gang of Four!

Ash and his friends arrive in a new town and hear about a competition called the Battle Pyramid. However, they also learn that the competition is only open to trainers who have earned the Frontier Symbols. Ash and his friends decide to start earning the symbols by challenging the Battle Frontier's facilities. Along the way, they come across a group of four powerful trainers known as the Frontier Brains, who are in charge of the Battle Frontier. Ash and his friends hope to learn from these trainers and eventually challenge them for their symbols. In this episode, the gang of four is finally gathered as they meet the final Frontier Brain, Lucy, who specializes in Ghost-type Pokémon.